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Biomedical subjects

M Carballo

Publications and source records attributed to M Carballo.

At least 19 recordsLinked to original sources
PubMed2006

Mutation profile of the MYO7A gene in Spanish patients with Usher syndrome type I.

Usher syndrome type I is the most severe form of Usher syndrome. It is an autosomal recessive disorder characterized by profound congenital sensorineural deafness, retinitis pigmentosa, and vestibular abnormalities. Mutations in the myosin VIIA gene (MYO7A) are responsible for Usher syndrome type 1B (USH1B). This gene is thought to bear greatest responsibility for USH1 and, depending on the study, has been reported to account for between 24% and 59% of USH1 cases. In this report a mutation screening of the MYO7A gene was carried out in a series of 48 unrelated USH1 families using single strand conformation polymorphism analysis (SSCP) and direct sequencing of those fragments showed an abnormal electrophoretic pattern. Twenty-five mutations were identified in 23 out of the 48 families studied (47.9%). Twelve of these mutations were novel, including five missense mutations, three premature stop codons, three frameshift, and one putative splice-site mutation. Based on our results we can conclude there is an absence of hot spot mutations in the MYO7A gene and that this gene plays a major role in Usher syndrome.

DNA Mutational Analysis↗
PubMed2006

Expanded donor criteria due to age: an effort rewarded.

The life expectancy of the current Spanish population is 78 years, with some 20% of the population aged over 65 years. The continuing increase in the demand for transplants has led to widening of the criteria for acceptance of donors without worsening the results, but without reducing transplant waiting lists or mortality. This has resulted in the need to include the concept of the expanded criteria donor (ECD). We undertook a retrospective study of 77 donors from a hospital with no neurosurgery service from January 2000 to December 2005. Four of the donors younger than 60 years of age (n = 38) were not appropriate (10.5%), whereas five of the donors older than 60 years of age (n = 39) were not appropriate (12.8%; P = NS). The older donors provided 47 used kidneys (60.2%) and 22 livers (56.4%), slightly fewer than those obtained from the younger donors, though the difference was not significant. Thus, ECDs, those older than 60 years of age, did not result in a significant loss of kidneys or livers available for transplantation. Other factors associated with systemic vascular disease and accompanying disorders could be determinant when predicting the usefulness of organs for transplantation.

Age Factors↗
PubMed2006

Identification of 14 novel mutations in the long isoform of USH2A in Spanish patients with Usher syndrome type II.

Mutations in USH2A gene have been shown to be responsible for Usher syndrome type II, an autosomal recessive disorder characterised by hearing loss and retinitis pigmentosa. USH2A was firstly described as consisting of 21 exons, but 52 novel exons at the 3' end of the gene were recently identified. In this report, a mutation analysis of the new 52 exons of USH2A gene was carried out in 32 unrelated patients in which both disease-causing mutations could not be found after the screening of the first 21 exons of the USH2A gene. On analysing the new 52 exons, fourteen novel mutations were identified in 14 out of the 32 cases studied, including 7 missense, 5 frameshift, 1 duplication and a putative splice-site mutation.

Adolescent↗
PubMed2006

[Follow-up of people with HIV].

The development of therapeutic and preventive vaccines would be an essential accomplishment needed to control the spread of HIV and is an absolute necessity especially in developing countries. The vaccines developed by Spanish groups in centers in our country are found to be among the most promising in the world. The upcoming work by the Spanish Group "RIS" on Therapeutic and Preventive Vaccines might place Spanish professionals in the front line in the international fight against AIDS.

Adult↗
PubMed2006

[Microbiological isolates in patients with febrile neutropenia and hematological neoplasias].

We studied the frequency of culture isolation, type of microorganism isolated and local pattern of resistance in 309 adult febrile neutropenic inpatients with hematological neoplasm, who were hospitalized between January 1998 and December 2003, in Caracas University Hospital (Hospital Universitario de Caracas), in Venezuela. There were 576 febrile neutropenic episodes. Organisms were isolated in 41% of 940 cultures. The most common organisms involved were gram-negative bacilli (48%), followed by gram-positive cocci (35.1%), fungal (11.5%) and other agents (5.4%). Coagulase-negative staphylococci (22.4%) and Escherichia coli (13.4%) were the most isolated; 58.5% of 479 agents isolated had an antibiogram; 62.2% of coagulase-negative staphylococci and 23.1% coagulase-positive staphylococci were oxacillin-resistant. We did not find any vancomycin-resistant organisms. The gram-negative antimicrobial sensitivity for imipenem was 96.2%, cefepime 81%, and ceftazidime 57.5%. Tazobactam-piperacillin and sulbactam-cefoperazone were tested in 26% of antibiograms and had activity of 57.1% and 77.5%, respectively. Fungi were not characterized. Betalactamases producing gram-negative bacilli were found. In general, micro-biological identification and local vigilance of antibacterial resistance pattern must be done routinely in these patients, in order to improve empiric therapy guidelines.

Adult↗
PubMed2004

De novo germline mutation in the serine-threonine kinase STK11/LKB1 gene associated with Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is an autosomal dominant disease, characterized phenotypically by mucocutaneous pigmentation and hamartomatous polyposis. Affected patients are at an increased risk of developing gastrointestinal and other malignancies. Mutations in the STK11/LKB1 (LKB1) gene, which encodes for a serine-threonine kinase, have been identified as a genetic cause of PJS. Molecular analysis of the LKB1 gene in a simplex case of PJS revealed a substitution of cytosine (C) for guanine (G) at codon 246 in exon 6, resulting in the Tyr246X mutation. The nucleotide substitution leads to a premature stop codon at the 246 residue, predicting a truncated protein and presumed loss of kinase activity. Analysis of DNA from both parents of the PJS patient did not show this mutation, which is therefore a de novo mutation. We isolated DNA from microdissected gastrointestinal hamartomatous polyps in the PJS patient and investigated the loss of heterozygosity (LOH) at the LKB1 locus by real-time fluorescence polymerase chain reaction genotyping using a fluorescent resonance energy transfer technique. The results suggest a different mechanism from LOH in the formation of hamartomatous polyps.

AMP-Activated Protein Kinase Kinases↗
PubMed2004

Testing alternative models for sexual isolation in natural populations of Littorina saxatilis: indirect support for by-product ecological speciation?

Two ecotypes of the rough periwinkle Littorina saxatilis occur at different shore levels, showing assortative mating for size and partial reproductive isolation when they meet at the mid-shore. This system represents a putative case of incomplete speciation in sympatry. Two processes contribute to the assortative mating: morph-specific microhabitat aggregation and mate choice. The estimation of mate choice coefficients in nature and a simulation of the aggregation effects on sexual isolation were used to disentangle these processes as well as to test alternative mechanisms of mate choice. Mate choice significantly increased the frequency of within-morph pairs and significantly decreased the frequency of between-morph pairs, whereas those pairs including at least one hybrid morph mated randomly. These results allow us to reject a discriminant mate choice and support a model of evolution of sexual isolation as a side-effect of size-assortative mating in a context of divergent natural selection for size in the population. This mechanism is more compatible with a model of incomplete by-product ecological speciation, as suggested by previous evidence.

Animals↗
PubMed2004

[Adhesion to the antiretroviral treatment].

The objective of the therapy antiretroviral is to improve the quality of life and the survival of the persons affected by the VIH through the suppression of the viral replication. Nevertheless one of the present problems is the resistant apparition of stumps to the new medicines caused by an incorrect management of the therapeutic plan; by an incorrect adhesion of the personal processing. Since the therapeutic success will depend, among others factors, and of important form of the degree of implication and commitment of the person affected, is a matter of identifying prematurely the possible situations concomitants (personal factors and of addiction, psycho-social, related to the processing and its possible secondary effects, associated factors to the own illness or even to the relation professional-patient) that can interfere in a correct adhesion. For it is necessary of the interaction multidisciplinary of the welfare team, and fundamental the work of nursing at the moment of to detect the possible determinant factors and the intervention definition of strategies arrived at by consensus with the own person, that they promote it or it improve. The quantification of the degree of adhesion (measure in %) values through various direct and indirect methods and should keep in mind in it takes of therapeutic decisions being able to come to be advised the suspension of the processing until obtaining to conscience to the person affected of the importance of a correct therapeutic compliance.

Anti-Retroviral Agents↗
PubMed2002

In vitro genotoxic evaluation of the medicinal plant Chenopodium ambrosioides L.

Chenopodium ambrosioides (Chenopodiaceae) is an anthelmintic herb used in Latin-America's folk medicine. The aim of this work is to evaluate genetic damage induced by decoction and infusion of this plant which were assayed in different concentrations (1, 10, 100, 1000 microg/ml), by addition of the extract to human lymphocyte cell cultures. The endpoints evaluated were chromosomal aberrations (CA), sister chromatid exchanges (SCE), cell proliferation kinetics (CPK) and mitotic indexes (MI). The repeated measure analysis of variance was used for statistic evaluation of the results. The results showed (a) a statistical increase in the percentage of cells with CA and in the frequency of SCE when cultures were exposed to both preparations of Paico, (b) a decrease in MI of both preparations assayed, although no modification in the CPK values either in the infusion or in the decoction was observed. These results suggest a possible genotoxic effect of both preparations, probably due to different active principles.

Anthelmintics↗
PubMed2002

Macrophage inducible nitric oxide synthase gene expression is blocked by a benzothiophene derivative with anti-HIV properties.

Nitric oxide (NO) has been shown to mediate multiple physiological and toxicological functions. The inducible nitric oxide synthase (iNOS) is responsible for the high output generation of NO by macrophages following their stimulation by cytokines or bacterial antigens. The inhibition of TNF alpha-stimulated HIV expression and the anti-inflammatory property of PD144795, a new benzothiophene derivative, have been recently described. We have now analyzed whether some of these properties could be mediated by an effect of PD144795 on NO-dependent inflammatory events. We show that PD144795 suppresses the lipopolysaccharide-elicited production of nitrite (NO(-)(2)) by primary peritoneal mouse macrophages and by a macrophage-derived cell line, RAW 264.7. This effect was dependent on the dose and timing of addition of PD144795 to the cells. Suppression of NO(-)(2) production was associated with a decrease in the amount of iNOS protein, iNOS enzyme activity and mRNA expression. The effect of PD144795 was partially abolished by coincubation of the cells with LPS and IFN gamma. However, the inhibitory effect of PD144795 was not abrogated by the simultaneous addition of LPS and TNF alpha, which indirectly suggests that the effect of PD144795 was not due to the inhibition of TNF alpha synthesis. Additionally, PD144795 did not block NF-kappa B nuclear translocation induced by LPS. Inhibition of iNOS gene expression represents a novel mechanism of PD144795 action that underlines the anti-inflammatory effects of this immunosuppressive drug.

Animals↗
PubMed2002

[Genetic and molecular characterization of 148 patients with autosomal dominant retinitis pigmentosa (ADRP)].

OBJECTIVE: Genetic characterization of a series of patients with autosomal dominant retinitis pigmentosa (ADRP). METHODS: All patients underwent complete ophthalmological examination including computerized perimetry, electroretinography and occasionally fluorescein angiography. Blood samples were drawn for genetic analysis of candidate genes namely rhodopsin (RHO), peripherin-RDS, ROM-1, CRX, RP1 and NRL. RESULTS: 148 ADRP index cases were examined at our hospital from June 1991 to September 2001. Genetic analysis detected the following mutations: 29 different families (19.5%) carried a RHO mutation among which the Pro-347-Leu was the most frequent one, five different RP-1 mutations (3.3%), 2 RDS mutations and one NRL mutation, which is the second reported in the world literature. CONCLUSIONS: RHO followed by RP1 are the most frequent ADRP-causing genes in our series as in other published ones, and RDS causes mainly macular dystrophies. Molecular characterization was possible in 37 families (25%) which is of great interest for visual prognosis and genetic counselling.

Amino Acid Substitution↗
PubMed2001

Mutations P51U and G122E in retinal transcription factor NRL associated with autosomal dominant and sporadic retinitis pigmentosa.

Retinitis pigmentosa (RP) is the most frequent form of inherited retinopathy. RP is genetically heterogeneous with autosomal dominant, autosomal recessive and X-linked forms. Autosomal dominant retinitis pigmentosa (adRP) accounts for about 20-25% of all RP cases. At least ten adRP loci have so far been mapped. However, mutations causing adRP have been identified only in four retina-specific genes: RHO (encoding rhodopsin) in approximately 20% of adRP families, peripherin/RDS (3-5% of adRP) and recently RP1 (Pierce et al., 1999, Sulivan et al., 1999) and NRL gene. Only one mutation in the NRL gene causing adRP has so far been reported (Bessant et al., 1999). Here we report a novel mutation Pro51Leu in an adRP Spanish family supporting that mutation in NRL is the cause of adRP. A second missense mutation Gly122Glu has been observed in a simplex RP patient that may represent a sporadic case of retinitis pigmentosa. Hum Mutat 17:520, 2001.

Base Sequence↗
PubMed2001

Sexual behaviour of heterosexual individuals with HIV infection naive for antiretroviral therapy in Italy.

BACKGROUND: Specific information about determinants of sexual behaviour of HIV infected heterosexuals, like injecting drug use (IDU), are essential to design interventions aimed at promoting safer sex practices. METHODS: We analysed data on sexual behaviour collected, between March 1997 and March 1999, through a self administered questionnaire among 1050 IDUs and 642 non-IDU heterosexuals enrolled in a prospective multicentre cohort study on the natural history of HIV infection. RESULTS: Among non-IDU heterosexuals, more women (48.5%) than men (25.1%) (p<0.001) reported that they were infected by HIV positive regular partners whose HIV status they were not aware of. Among the 1119 heterosexual males, one fifth reported having had more than 25 sexual partners during their lifetime. Condom use in the last sexual intercourse was more common among heterosexual IDUs (64.9%) than among non-IDU heterosexual males (58.3%) (p=0.05). Heterosexual IDU males were more likely (66.7%) than non-IDU heterosexuals (50.6%) to have an HIV negative partner (p<0.001). Of the 573 heterosexual females studied, 10.2% reported having had more than 25 lifetime sex partners. This proportion was higher among heterosexual IDUs (18.8%) than among non-IDU heterosexuals (4.3%) (p<0.001). Nearly 50% of the women in both groups reported having used a condom in the last intercourse. Almost 57% of heterosexual IDUs had a current HIV negative partner, compared with 34.9% non-IDU heterosexuals (p<0.001). In both sexes, the findings from univariate analysis were confirmed by multiple logistic regression analysis. CONCLUSIONS: This study identified some important differences, in both males and females, in sexual lifestyles according to injecting drug use (for example, in terms of HIV negative partners). This observation indicates the need to tailor HIV prevention messages according to history of injecting drug use.

Adult↗
PubMed2001

Migration, refugees, and health risks.

Migration both voluntary and forced is increasing all over the world. People are moving in larger numbers faster and further than at any other time in history. This is happening at a time when many countries are ill-prepared to deal with a changing demography and when policies and attitudes to population movement and immigration are hardening. The health implications of this are many, and, in some cases, illness and death rates associated with migration are exacerbated by a lack of policies needed to make migration a healthy and socially productive process. From a public health point of view, this is having and will continue to have serious ramifications for the people that move, the family they leave behind, and the communities that host the newcomers.

Adult↗